The Texas-based fast food chain is thanking customers for 65 years of service.

According to a press release from Whataburger, customers who visit participating stores throughout the U.S. can take advantage of a freebie the company is offering as a token of thanks:

This Saturday, Aug. 8, 2015 from 11 a.m. to 11 p.m., at participating locations, Whataburger will offer all guests who order a regular meal (including a sandwich, fries and a beverage) an upgrade to a large fries and a 44-ounce fountain drink or tea. Whataburger Jr. meals include an upgrade to medium fries and a 32-ounce fountain drink or tea.

The first Whataburger opened on August 8, 1950 by Harmon Dobson in Corpus Christi, Texas.

"We want to share our thanks in a big way to all of our customers who have enjoyed our classic Whataburgers, just like Mr. Dobson proudly established at his first burger stand in Corpus Christi, Texas 65 years ago," said Rob Rodriguez, Senior Vice President of Operations.